| 197 | } |
| 198 | |
| 199 | bool TNetSocket::RecvFrom(char* buf, int* size, sockaddr_in6* fromAddress) const { |
| 200 | for (;;) { |
| 201 | int rv; |
| 202 | if (s->IsRecvMsgSupported()) { |
| 203 | const NNetlibaSocket::TIoVec v = NNetlibaSocket::CreateIoVec(buf, *size); |
| 204 | NNetlibaSocket::TMsgHdr hdr = NNetlibaSocket::CreateRecvMsgHdr(fromAddress, v); |
| 205 | rv = s->RecvMsg(&hdr, 0); |
| 206 | |
| 207 | } else { |
| 208 | sockaddr_in6 dummy; |
| 209 | TAutoPtr<NNetlibaSocket::TUdpRecvPacket> pkt = s->Recv(fromAddress, &dummy, -1); |
| 210 | rv = !!pkt ? pkt->DataSize - pkt->DataStart : -1; |
| 211 | if (rv > 0) { |
| 212 | memcpy(buf, pkt->Data.get() + pkt->DataStart, rv); |
| 213 | } |
| 214 | } |
| 215 | |
| 216 | if (rv < 0) |
| 217 | return false; |
| 218 | // ignore empty packets |
| 219 | if (rv == 0) |
| 220 | continue; |
| 221 | // skip small packets |
| 222 | if (rv < UDP_LOW_LEVEL_HEADER_SIZE) |
| 223 | continue; |
| 224 | *size = rv; |
| 225 | ui32 pktCrc = *(ui32*)buf; |
| 226 | ui32 crc = CalcChecksum(buf + UDP_LOW_LEVEL_HEADER_SIZE, rv - UDP_LOW_LEVEL_HEADER_SIZE); |
| 227 | if (!CrcMatches(pktCrc, crc + PortCrc, *fromAddress)) { |
| 228 | // crc is really failed, discard packet |
| 229 | continue; |
| 230 | } |
| 231 | return true; |
| 232 | } |
| 233 | } |
| 234 | |
| 235 | void TNetSocket::Wait(float timeoutSec) const { |
| 236 | s->Wait(timeoutSec); |